The rates of new cancer cases and cancer deaths have fallen in the U.S. over the past few decades. But certain cancers are becoming more common among younger Americans, and researchers think obesity may be to blame, finds a new report from the American Cancer Society and the National Cancer Institute.
Rates of six different cancers that are associated with obesity increased among adults ages 25-49 between 1995 and 2014, according to the research, which was published in the journal Lancet Public Health and based on information in the Cancer in North America database.
These cancers includes:
- multiple myeloma,
- colorectal, endometrial
Even though cancer most often strikes older adults, the sharpest increases were found in younger age groups. Pancreatic cancer exemplifies the pattern: Between 1995 and 2014, incidence of the disease rose by 0.77% annually among adults ages 45-49; by 2.47% among those ages 30-34; and by 4.34% among those ages 25-29. Kidney cancer had the sharpest annual increase for young Americans: 6.23% between 1995 and 2014.
While some cancers have a fairly clear cause — like smoking for lung cancer, or HPV for cervical cancer — many are brought on by a confluence of chance, genetics and lifestyle and health factors. Obesity is among the most impactful of these. Research has linked excess body weight to about 40% of cancer cases in the U.S., and it’s a risk factor for common types like breast, ovarian and livercancer, as well as those highlighted in the new study. By 2014, obesity accounted for 60% of endometrial cancers, 36% of gallbladder cancers, 33% of kidney cancers, 17% of pancreatic cancers and 11% of multiple myeloma among adults ages 30 and older, the new paper says.